1. Field of the Invention
This invention relates to new amphoteric surfactants, and more particularly to specific ethoxylated amines which are quaternized and partially sulfated; methods of making same and to methods of use therefor. More particularly, this invention relates to novel derivatives of certain amphoteric, water-soluble compounds that are characterized by the following formula ##STR2## wherein R represents a C.sub.8 -C.sub.14 aliphatic radical; R.sub.1 represents a C.sub.1 -C.sub.4 lower alkyl radical; R.sub.2 and R.sub.3 each represent H or CH.sub.3 ; M.sub.1 and M.sub.2 represent cations of hydrogen, ammonium, alkyl ammonium, alkali metal, or an equivalent of alkaline earth metal; n is an integer having an average value of from 5 to 10; s and t can either be 0 or 1 but both cannot be simultaneously 0; and A represents an anionic radical such as hydroxide, halogen, sulfate, alkyl sulfate, etc. Such derivatives are useful as essentially non-irritating and high foaming amphoteric surface active agents for shampoo and other cosmetic applications. Preferably, R in such derivative is a naturally derived or a synthetic alkyl group containing an average of 10-12 carbon atoms.
2. Description of the Prior Art
The prior art describes many varied types of amine sulfonates, sulfates and related compounds. For example, hydroxy alkyl and dihydroxy alkyl derivatives of higher fatty acid amines have been sulfated with chlorosulfonic acid to yield the sulfate. However, none of these compounds have achieved significant commercial acceptance and in none are found all of the desirable properties of the instant invention.
Also known in the art, as, e.g. from U.S. Pat. No. 2,185,163 are polyoxyalkylene ammonium compounds, formed from reaction at elevated temperatures of tertiary amine oxides with alkylene oxides in the presence of water, and such compounds are useful as wetting and emulsifying agents. However, these known materials do not have the capacity to be high foaming and simultaneously non-irritating to the hair, skin, and eyes as is characteristic of the present invention.
While the common soaps are inexpensive and good cleansing agents, they have certain undesirable characteristics, among which are: poor foamability and cleaning in hard water; when used for shampooing, which is the most preferred embodiment of this invention, they sometimes form insoluble salts which deposit on the hair, thereby imparting a dull appearance thereto, and generally require rinses of acidic nature for their removal; they are irritating to the eyes; tend to precipitate at pH values of 7 or below; and foam poorly at pH values of 6-7.
While the amides of said amino acids do exhibit better resistance to hard water when compared with common soaps, they exhibit poor foam and poor foam stability in hard water; they dull hair as do the common soaps but to a lesser extent when used as shampoos and they precipitate out in aqueous media at pH 4.5.